The Palace Letters: New fight to release correspondence between Queen, G-G in lead-up to Whitlam dismissal

Gough Whitlam's biographer has launched a legal bid to force the National Archives to open a secret trove of correspondence between the Queen and former Governor-General Sir John Kerr in the run-up to the dismissal of the Whitlam government in 1975.

"I think undoubtedly they'll show that the Queen was far more aware of the circumstances leading to the dismissal than we have previously thought," she told 7.30.

Because the correspondence was categorised as "personal and private" when it was bequeathed to the National Archives, unlike his official records, Kerr's estate was able to set the conditions for its release.

Those conditions state the dossier is not to be opened until 2027, and then only with the permission of the current Governor-General and the monarch.

"They are absolutely pivotal to our history, and it's galling that the Queen and the Palace in general should retain any sort of veto over our access as Australians to critical documents in our history," Professor Hocking said.

The unprecedented legal challenge in the Federal Court will argue the documents should be seen as Commonwealth records and released in accordance with the Archives Act.

'They aren't personal letters, they are crucial to our history'

Historian and author Thomas Keneally backs Professor Hocking's bid.

"They aren't personal letters, they are letters that are crucial to our history," he told 7.30.

A handful of extracts from Kerr's letters to the Palace quoted in his own journal show that from as early as September 1975, the Governor-General had raised the prospect of him sacking of the Government, and of his own dismissal by Whitlam.

"The moment he set that out to the Queen she was already involved because the Queen from that point had options that she could take," Professor Hocking said.

"One of the options was to alert the prime minister Gough Whitlam to the fact that the Governor-General was speaking about these very extreme possibilities ... Now, from all accounts she chose not to do that."

Kerr always maintained the Palace had no knowledge of his plan to sack the Whitlam government and the Queen herself has never spoken about the crisis.

In 2001 the Queen's assistant private secretary at the time of the dismissal, Sir William Heseltine, hinted the Queen was unhappy with the matter unfolding as it did.

"My own feeling is that she would have advised him to play out the situation a little longer," he told an ABC documentary.